Tag Info

Unfortunately, we are all still "confuzzled" by how memory works. We are far from a complete understanding of how memory is stored and recalled. Nonetheless, we do know a little, so read on. Your understanding of basic neural function is almost correct. First, an individual neuron will signal through its single axon onto the dendrites of many downstream ...

You would need to live a long, long, long, long time for this to become remotely problematic. Your question seems to suppose that a memory is "stored" by a neuron, and since neurons have mass, then the more memories we have the more our brains will weigh. Actually, neurogenesis is pretty rare in the adult brain--most of the cortex is fixed, and new neurons ...

Its not clear that this is true. Working with animals has been a little disconcerting over the past 50-60 years. In the distant past, I think most evolutionary anthropologists and their like bought into the idea that humans were completely uniquely intelligent and spiritual. But the more we try to define human sensibilities apart from other animals, the ...

Well, Erickson et al (2011) attribute the increase in brain volume in the aerobic exercise group to brain-derived neurotrophic factor (BDNF). Specifically (p. 3020): In fact, we found here that changes in serum BDNF levels were associated with changes in anterior hippocampal volume; an important link because the hippocampus is rich in BDNF, and BDNF ...

The newest and most accurate method (far more accurate than older extrapolating/manual counting methods (Stereology) and yielding some surprising results) to estimate number/density of neurons/cells in brains is Isotropic Fractionator to my knowledge. Using this keyword you find some recent papers, comparing different brain areas (cerebral cortex, ...

I haven't read anything particularly about dendrites being reshaped, though I would expect them to be as flexible as other parts of the cells. The more commonly discussed topic (in my literary experience) is reshaping of the axon's branches before forming synaptic terminals. These branches are not fixed even in adults - neurons can grow new and retract old ...

I would like to point out some ways your understanding is wrong. "Neural networks" are usually a computer science term, only very, very loosely based on actual neural networks. The idea of layers in a neural network is pretty much an invention of computer science, it doesn't really reflect the reality. Also, neurons are not binary switches. It isn't so much ...

Its pretty well established that there are photoreceptors in cells besides the cones and rods in the retina of the eye. Humans and most animals have four light receptor genes known (so far). In addition to Rhodopsin - there are the short, med and long wavelength opsin genes. While they are mostly expressed in the retina of the eye, they can be found in ...

I would say no. You question somehow implies that somatosensory cortex is equally distributed among the different sensory areas of the body, whereas in the reality this is the known "cortical homunculus" concept of how this distribution looks: If you look at this representation you'll see that chest and legs take only about one third to one fourth of the ...

You are completely right with your guess that is was Ramón y Cajal who first described these cells in his famous monograph "Histologie de systeme nerveux de l'homme et des vertebres." published in Paris Maloine in 1911. Since the only method he had at his disposal was Golgi's staining which is a pure anatomical staining (there is no living cell left in the ...

Microtubules are a structure in the cytoskeleton, they are rope like polymers that grow to a length of about 25 micrometers (25000 nm), and have an outer-diameter of around 25 nm. For comparison, the mean spacing between atoms is on the order of 0.1 to 0.2 nm; so the micro tubule really is micro: about 200 atoms across. In terms of quantum effects though, ...

There are a number of different wiring scenarios that could lead to this type of behavior, even in a dissociated neuronal cell culture. The two major cases are neurons that are truly isolated from each other, and collections of neurons that connect together. Since your question refers to firing and synchronized bursts, I'll restrict my discussion to the ...

As you've already mentioned, cells near the primate macula tend to make one to one connections. Due to this lack of convergence they can be somewhat smaller than normal cells (particularly in the size of their dendritic arbors) earning them the moniker "midget" ganglion and bipolar cells (also P cells). By reducing the magnitude of photoreceptor ...

We already remove old ones and create new ones. I doubt you remember most of Geometry, for instance. As for capacity, this article from Scientific American gives a good overview of what we can estimate with our current knowledge. For comparison, if your brain worked like a digital video recorder in a television, 2.5 petabytes would be enough to hold ...